AIR CLI: implement air run --watch (stream logs until completion)

[riddhibhagwat-db]

Changes & Why

After submitting a workload, --watch follows the run's logs to completion and exits with the run's outcome, reusing the same Bricklens-with-MLflow-fallback pipeline as air logs.

• Text mode: prints "Submitted run", the dashboard link, and "Monitoring run and streaming logs...", then streams the logs.
• JSON mode: emits a SUBMITTED event with the run id, a STATUS event on each lifecycle transition, the streamed LOG/ALERT events, and a closing terminal-status envelope (SUCCESS/FAILED/CANCELED) — matching the Python CLI's --watch JSONL contract.
• Without --watch, the plain submit path now prints a tip about --watch.
• STATUS events are watch-scoped (opt-in via logRequest.onStatusChange), so the merged air logs output is unchanged.

--dry-run still takes precedence over --watch (nothing is submitted or streamed).

Tests

Unit tests (experimental/air/cmd/)

• logbricklens_test.go: Bricklens client query/path serialization + time_unix_nano parsing
• logstream_test.go: fallback classification, status projection, --minutes/tail math, page dedup/ordering, retry-then-fallback, JSONL/ALERT emit, Ctrl-C exit
• logmlflow_test.go: MLflow chunk discovery/listing, attempt-prefix layout, no-logs exit-code parity
• logs_test.go: air logs command: flag validation, completed-run tail, Bricklens→MLflow fallback, past-retry static view
• run_watch_test.go: air run --watch: text stream, JSON SUBMITTED→STATUS→LOG→terminal envelope, failed-run exit code, dry-run precedence

Acceptance tests (acceptance/experimental/air/)

• logs/ : text/JSON streaming, --minutes, --lines, --lines 0, --retry, mutual-exclusion errors, invalid id, negative node, --download-to
• logs-mlflow-fallback/ : Bricklens FEATURE_DISABLED → MLflow fallback → no-logs (text & JSON)
• run/ : dry-run, --override, config validation, --watch ignored under --dry-run
• run-submit/ : real submit payload + --watch tip line
• help/ : air --help, air logs --help command-tree pins

Manual verification:
Properly monitors and outputs logs from runs on manual test:

[eng-dev-ecosystem-bot]

Integration test report

Commit: e74adb3

Run: 30400984356

	Env	❌​FAIL	🟨​KNOWN	💚​RECOVERED	🙈​SKIP	✅​pass	🙈​skip	Time
❌​	aws-cli-is linux	8	1	3	4	320	1035	7:42
❌​	aws-cli-is windows	8	1	3	4	322	1033	17:43
❌​	azure-cli-is linux	8	1	3	4	320	1034	7:24
❌​	azure-cli-is windows	8	1	3	4	322	1032	19:44
❌​	gcp-cli-is linux	8	4		4	319	1036	10:52
❌​	gcp-cli-is windows	8	4		4	321	1034	17:11

16 interesting tests: 8 FAIL, 4 KNOWN, 4 SKIP

	Test Name	aws-cli-is linux	aws-cli-is windows	azure-cli-is linux	azure-cli-is windows	gcp-cli-is linux	gcp-cli-is windows
🟨​	TestAccept	🟨​K	🟨​K	🟨​K	🟨​K	🟨​K	🟨​K
❌​	TestAccept/bundle/deploy/mlops-stacks	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F
❌​	TestAccept/bundle/deploy/mlops-stacks/DATABRICKS_BUNDLE_ENGINE=direct	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F
❌​	TestAccept/bundle/deploy/mlops-stacks/DATABRICKS_BUNDLE_ENGINE=terraform	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F
❌​	TestAccept/bundle/generate/auto-bind	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F
❌​	TestAccept/bundle/generate/auto-bind/DATABRICKS_BUNDLE_ENGINE=terraform	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F
🙈​	TestAccept/bundle/invariant/no_drift	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S
❌​	TestAccept/bundle/resources/grants/volumes	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F
❌​	TestAccept/bundle/resources/grants/volumes/DATABRICKS_BUNDLE_ENGINE=direct	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F
❌​	TestAccept/bundle/resources/grants/volumes/DATABRICKS_BUNDLE_ENGINE=terraform	❌​F	❌​F	❌​F	❌​F	❌​F	❌​F
🙈​	TestAccept/bundle/resources/vector_search_endpoints/drift/recreated_same_name	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S
🙈​	TestAccept/bundle/resources/vector_search_indexes/recreate/embedding_dimension	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S
🙈​	TestAccept/ssh/connection	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S	🙈​S
🟨​	TestFetchRepositoryInfoAPI_FromRepo	💚​R	💚​R	💚​R	💚​R	🟨​K	🟨​K
🟨​	TestFetchRepositoryInfoAPI_FromRepo/root	💚​R	💚​R	💚​R	💚​R	🟨​K	🟨​K
🟨​	TestFetchRepositoryInfoAPI_FromRepo/subdir	💚​R	💚​R	💚​R	💚​R	🟨​K	🟨​K

[maggiewang-db]

Can you do a manual test with the fallback mlflow path?

[maggiewang-db]

Isaac claims this terminalStatus is never updated in the fallback mlflow code path. Can you double check?

[riddhibhagwat-db]

fixed, thanks for the catch!